Run Cucumber Tests in Parallel

Run automated tests on multiple browsers in parallel with Cucumber Java using BrowserStack Automate.

Introduction

On BrowserStack, you can run multiple Cucumber tests at the same time across various browser, device, and OS combinations. This is called Parallel Testing. Parallel Testing gives you the same benefits as running a multi-threaded application.

With Parallel Testing, you can run the same test on different browser/device combinations, namely cross-browser testing, or run different tests on the same or different browser/device combinations. Parallel Testing helps you reduce the run time of your test suite, resulting in faster build times and faster releases.

This guide will help you:

1. Run your first parallel test
2. Understand your test runner

Prerequisites

If you have already run your first test, you can skip the prerequisites.

• BrowserStack Username and Access key, which you can find in your account settings. If you have not created an account yet, you can sign up for a Free Trial or purchase a plan.
• Maven is installed on your machine, Maven environment variables are set, and Maven bin is added to system path, $PATH. Check out the official website to download the latest version of Maven.
• Git installed on your machine.
• Java installed on your machine.

Run your first parallel test

1. Clone the cucumber-java-browserstack sample repo on GitHub using the following command:
   
   

   git clone https://github.com/browserstack/cucumber-java-browserstack.git
   cd cucumber-java-browserstack
   

2. Install the required dependencies by running the following command in your command-line:
   
   

    mvn install
   

3. Set your BrowserStack credentials and browser/devices where you want to run your test in the cucumber-java-browserstack/src/test/resources/conf/parallel.conf.json file as follows:
   
   

   parallel.conf.json

    {
      "server": "hub.browserstack.com",
      "user": "YOUR_USERNAME",
      "key": "YOUR_ACCESS_KEY",
   
      "capabilities": {
        "build": "cucumber-java-browserstack",
        "name": "parallel_test",
        "browserstack.debug": true
      },
   
      "environments": [
        {
          "browser": "chrome"
        },
        {
          "browser": "firefox"
        },
        {
          "browser": "safari"
        }
      ]
    }
   

4. Run your tests in parallel on BrowserStack using the following command:
   
   

    mvn test -P parallel
   

5. View your tests on BrowserStack on the BrowserStack Automate Dashboard.

Understand your test runner

The RunWebDriverCucumberTests.java file in the cucumber-java-browserstack/src/test/java/com/browserstack directory includes the logic that helps run test in parallel on BrowserStack.

@CucumberOptions(
    glue = "com.browserstack.stepdefs",
    plugin = {
      "pretty",
      "html:reports/tests/cucumber/html",
      "timeline:reports/tests/cucumber/timeline",
      "junit:reports/tests/cucumber/junit/cucumber.xml",
      "testng:reports/tests/cucumber/testng/cucumber.xml",
      "json:reports/tests/cucumber/json/cucumber.json"
    }
)
public class RunWebDriverCucumberTests {

    private TestNGCucumberRunner testNGCucumberRunner;
    private Local local;
    private static final ThreadLocal<ManagedWebDriver> threadLocalWebDriver = new ThreadLocal<>();

    @BeforeClass(alwaysRun = true)
    public void setUpClass() {
        testNGCucumberRunner = new TestNGCucumberRunner(this.getClass());
    }

    private synchronized static void setThreadLocalWebDriver(ManagedWebDriver managedWebDriver) {
        threadLocalWebDriver.set(managedWebDriver);
    }

    public synchronized static ManagedWebDriver getManagedWebDriver() {
        return threadLocalWebDriver.get();
    }

    @Test(groups = "cucumber", description = "Runs Cucumber Feature", dataProvider = "scenarios")
    public void feature(PickleWrapper pickleWrapper, FeatureWrapper featureWrapper, ManagedWebDriver managedWebDriver) {
        if(Utility.isLocal(managedWebDriver) && local==null){
            local = new Local();
            Utility.startLocal(local, managedWebDriver);
        }
        managedWebDriver.setTestName(pickleWrapper.getPickle().getName());
        setThreadLocalWebDriver(managedWebDriver);
        testNGCucumberRunner.runScenario(pickleWrapper.getPickle());
    }

    @DataProvider(name = "scenarios", parallel = true)
    public Iterator<Object[]> scenarios() {
        Object[][] scenarios = testNGCucumberRunner.provideScenarios();
        //Get Iterator of Object arrays consisting PickleWrapper, FeatureWrapper and ManagedWebDriver
        return new LazyInitWebDriverIterator(scenarios);
    }

    @AfterClass(alwaysRun = true)
    public void tearDownClass() {
        if(local != null){
            try {
                local.stop();
            } catch (Exception e) {
                throw new Error("Unable to stop BrowserStack Local.");
            }
        }
        if (testNGCucumberRunner == null) {
            return;
        }
        testNGCucumberRunner.finish();
    }
}

Next steps

After you have successfully run your first parallel test using BrowserStack, you can explore the following sections:

• Test on private websites that are hosted on your internal networks
• Plan the number of parallels you need
• What are queued tests in Parallel Testing on BrowserStack